1. Technical Field
The present invention relates to an AD converting apparatus, an AD converting method, a control apparatus, and a program. In particular, the present invention relates to an AD converting apparatus, an AD converting method, a control apparatus, and a program for converting an analog input signal into a digital output signal using a plurality of AD converters.
2. Related Art
An interleave-type AD converting apparatus with a high sampling rate is known as in, for example, Japanese Patent Application Publication No. 2005-347967. The interleave-type AD converting apparatus is provided with a plurality of AD converters that are supplied with sampling clocks that differ from each other by a prescribed phase, and a combining section that sequentially selects one sample at a time of the signals output by the AD converters and combines these sampled signals.
The AD converting apparatus described above corrects each of a plurality of signals output by a plurality of AD converters, where each signal is corrected according to a frequency characteristic of the corresponding AD converter. In this way, the AD converting apparatus can accurately convert an analog input signal into a digital output signal, even when each AD converter has a different frequency characteristic.
However, each AD converter has an error that causes a curve representing the relation between the amplitude of the input signal and the data value of the AD-converted output signal to deviate from the ideal curve, e.g. a straight line. The characteristic that causes the curve representing the relation between the amplitude of the input signal and the data value of the AD-converted output signal to deviate from the ideal curve is known as the “non-linear characteristic.” An interleave-type AD converting apparatus causes spurious components to be included in the output signal when the AD converters have different non-linear characteristics, and this decreases the dynamic range of the output signal.